UI tasks

[Sheraff]

• [x] audio player
• [x] search
• [x] artist view
  • [x] show tracks in addition to albums (or at least, tracks that aren't in any album)
• [x] album view
• [x] genre view
  • [x] to have interesting stuff to show on a "genre view" we'd need better data on relationships between genres
• [x] currently playing
• [x] playlist view
• [x] home / recently played / most played
• [ ] #70
• [x] library view
  • [x] artists
  • [x] albums
  • [x] playlists
  • [x] genres
  • [x] tracks